Light-duty liquid CDL) or gel detergent compositions useful for manual dishwashing are well known in the art. Such products are generally formulated to provide a number of widely diverse performance and aesthetics properties and characteristics. First and foremost, liquid or gel dishwashing products must be formulated with types and amounts of surfactants and other cleaning adjuvants that will provide acceptable solubilization and removal of food soils, especially greasy soils, from dishware being cleaned with, or in aqueous solutions formed from, such products.
Heavily soiled dishware can present special problems during manual dishwashing operations. Articles such as plates, utensils, pots, pans, crockery and the like may be heavily soiled in the sense that relatively large amounts of food soils and residues may still be found on the dishware at the time such soiled dishware is to be manually washed. Dishware may also be heavily soiled in the sense that food soil residues are especially tenaciously adhered or stuck to the surfaces of the dishware to be cleaned. This can result from the type of food soils present or from the nature of the dishware surfaces involved. Tenacious food soil residues may also result from the type of cooking operations to which the soiled dishware had been subjected.
When heavily soiled dishware is to be manually cleaned, very often highly concentrated, or high concentrations of, dishwashing detergent products are used. Frequently, this will involve direct application to the soiled dishware of a liquid or gel product in its undiluted or neat form. During such applications, the pH characteristics of the dishwashing composition can have a significant effect on the ability of the composition to solubilize and remove food soils such as greasy soils. Product pH furthermore can determine the effectiveness of conventional aqueous dishwashing solutions in removing greasy soils from dishware. In general, aqueous dishwashing solutions that are more alkaline in nature are more effective at removing such soils.
Also, when highly concentrated or neat detergent products are applied directly to soiled dishware, it is important that the dishwashing composition have Theological characteristics which keep it from too quickly running off of the soiled dishware. Product rheology, however, should not interfere with product dispensibility or with the ability of the product to readily dissolve in water to form conventional aqueous dishwashing solutions.
Finally, in addition to being useful for cleaning dishware, LDL or gel compositions will also desirably possess other attributes that enhance the aesthetics or consumer perception of the effectiveness of the manual dishwashing operation. Thus, useful hand dishwashing liquids or gels should also employ materials that enhance the sudsing characteristics of the wash solutions formed from such products. Sudsing performance entails both the production of a suitable amount of suds in the wash water initially, as well as the formation of suds which last well into the dishwashing process.
Given the foregoing, there is a continuing need to formulate manual dishwashing liquids and gels that provide an acceptable and desirable balance between cleaning performance, in both concentrated direct application and aqueous washing solution contexts, product rheology and product aesthetics. Accordingly, it is an object of the present invention to provide light-duty liquid or gel dishwashing compositions which are especially effective at removing food soils from dirty dishware when such compositions are used in the context of a manual dishwashing operation.
It is a further object of this invention to provide such compositions having desirable pH characteristics for use in either a direct application to dishware context or in an aqueous dishwashing solution context.
It is a further object of this invention to provide such compositions having desirable Theological characteristics for use in either a direct application to dishware context or in an aqueous dishwashing solution context.
It is a further object of the present invention to realize such compositions that provide suitable and desirable sudsing performance.
It has been found that certain selected combinations of surfactants, suds boosters, pH control agents and other adjuvants can be made to provide dishwashing compositions that achieve the foregoing objectives. The elements of these selected combinations of ingredients are described as follows: